/*
 * Copyright (C) 2009 The Guava Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.common.collect.testing.testers;

import com.google.common.annotations.GwtCompatible;
import com.google.gwt.core.client.GWT;

/**
 * The emulation source used in GWT.
 *
 * @author Hayward Chan
 */
@GwtCompatible(emulated = true)
final class Platform
{

    // Use fewer steps in the ListIteratorTester in ListListIteratorTester because it's slow in prod
    // mode.
    static int listListIteratorTesterNumIterations()
    {
        // TODO(hhchan): It's 4 in java.  Figure out why even 3 is too slow in prod mode.
        return GWT.isProdMode() ? 2 : 4;
    }

    // Use fewer steps in the IteratorTester in CollectionIteratorTester because it's slow in prod
    // mode..
    static int collectionIteratorTesterNumIterations()
    {
        return GWT.isProdMode() ? 3 : 5;
    }

    // TODO: Consolidate different copies in one single place.
    static String format(String template, Object... args)
    {
        // start substituting the arguments into the '%s' placeholders
        StringBuilder builder = new StringBuilder(template.length() + 16 * args.length);
        int templateStart = 0;
        int i = 0;
        while (i < args.length)
        {
            int placeholderStart = template.indexOf("%s", templateStart);
            if (placeholderStart == -1)
            {
                break;
            }
            builder.append(template.substring(templateStart, placeholderStart));
            builder.append(args[i++]);
            templateStart = placeholderStart + 2;
        }
        builder.append(template.substring(templateStart));

        // if we run out of placeholders, append the extra args in square braces
        if (i < args.length)
        {
            builder.append(" [");
            builder.append(args[i++]);
            while (i < args.length)
            {
                builder.append(", ");
                builder.append(args[i++]);
            }
            builder.append("]");
        }

        return builder.toString();
    }

    private Platform()
    {
    }
}
